Migraines can be more than just a pain in the head. Basilar migraines, once known as basilar artery migraines or BAMs, are an extraordinarily rare but potentially life-threatening variant of the classic migraine with aura.

Basilar migraine symptoms are caused by constriction of the basilar artery, which supplies blood to the brain stem. BAMs were originally thought to affect only young women and adolescent girls, but research shows that while they are primarily a problem for these groups they can occur in people of all ages and genders.

During the aura phase, basilar migraine symptoms may include loss of balance, double vision or partial vision loss, lack of coordination, numbness on one or both sides of the body, weakness, dizziness or confusion and severe vomiting. The symptoms typically last an hour or less and disappear when the headache begins, but may last as long as days after the headache pain has disappeared. Some basilar migraine sufferers pass out or lose consciousness during the aura phase as well. In extremely rare cases, they may even slip into a coma that can last hours or days.

The danger of basilar migraines is that they can lead to a transient ischemic attack (TIA) or stroke. A transient ischemic attack is essentially a miniature stroke resulting from a temporary interruption of the flow of blood to the brain. Unlike strokes, TIAs have not been shown to cause permanent damage to the brain and most neurological problems that arise from them, like slurred speech or weakness on one side, clear up within twenty-four hours of the attack.

The basilar artery is located at the back of head. The headache associated with basilar migraines is usually a severe throbbing ache on both sides of the back of the head, as opposed to the unilateral temple throbbing more commonly associated with migraines.